(1) Field of the Invention
The present invention relates to methods and apparatus for wide area detection, analysis and monitoring of seismic events and especially to use of existing communications infrastructure.
(2) Description of the Art
In areas which are prone to earthquakes, monitoring for tremors, i.e. seismic waves may be routinely performed. The detection of seismic waves can be used in an earthquake warning system. The monitoring may involve detecting seismic waves above a certain magnitude threshold that are propagating toward sensitive areas such as population centres or important installations and infrastructure. Detection of shock waves of significant magnitude before they reach the sensitive area may allow a short time for precautionary measures to be taken. If sufficient time is available personnel may be evacuated from high risk areas and/or assembled in specially protected areas. Trains could be slowed or stopped and bridges closed to traffic. Equipment presenting an explosion, fire or pollution risk or other hazard if damaged in an earthquake, such as oil and gas pipelines for example, could be shut down.
Detection and monitoring of a series of minor shocks can also be used by seismologists in attempting earthquake prediction and may allow identification of periods of elevated earthquake risk.
Seismic data acquired during an earthquake can be useful for determining the likelihood of damage to infrastructure such as bridges, dams and the like. The data is also useful for seismologists for use in modelling earthquakes.
Monitoring of seismic data in coastal regions may also be performed as part of a tsunami warning system.
Earthquake warning systems generally require a relatively large number of seismic sensors such as seismographs, accelerometers, geophones etc. which are deployed over a wide area with high speed communications links to a control centre. This can involve a significant number of sensors deployed over a wide area and, in some cases, in different countries.